objective-c - 在 OS X Yosemite 中对 ViewController 进行动画自定义演示

Question

我想实现新方法，我在 Google 和 Stack Overflow 上搜索了很多，但没有找到示例。

- (void)presentViewController:(NSViewController *)viewController animator:(id <NSViewControllerPresentationAnimator>)animator

此方法在 OSX 10.10 中可用，此方法需要实现具有这两个方法的协议(protocol) NSViewControllerPresentationAnimator

- (void)animatePresentationOfViewController:(NSViewController *)viewController fromViewController:(NSViewController *)fromViewController 

- (void)animateDismissalOfViewController:(NSViewController *)viewController fromViewController:(NSViewController *)fromViewController 

这些方法允许我们在两个 NSViewController 之间做自定义动画我需要一个实现示例，我有这段代码:

- (IBAction)openTask:(id)sender {
    
    NSStoryboard *storyboard = [NSStoryboard storyboardWithName:@"Main" bundle:[NSBundle mainBundle]];
    Tasks *task = [storyboard instantiateControllerWithIdentifier:@"tasks"];
    [self presentViewController:task animator:self];
 
}

- (void)animatePresentationOfViewController:(NSViewController *)viewController
                         fromViewController:(NSViewController *)fromViewController
{
    
    
}

- (void)animateDismissalOfViewController:(NSViewController *)viewController
                      fromViewController:(NSViewController *)fromViewController
{
    
    
}

任何人都可以帮我举个例子说明我如何实现这种转变吗？

Answer 1

这是一个在新 View Controller 的 View 中淡出的简单版本 (Swift)。我相信您可以将其转化为 Objective-C。

你会想要实际使用自动布局而不是仅仅改变框架，但这会使示例更长一点(不太难。只需在添加 View 后添加约束)

我不确定您是否也需要 viewcontroller containment。然后需要适当调用 addChildViewController 等等。也许有人可以阐明何时可能需要这样做，或者在任何情况下这实际上都是好的做法。

class MyTransitionAnimator: NSObject, NSViewControllerPresentationAnimator {

    func animatePresentationOfViewController(viewController: NSViewController, fromViewController: NSViewController) {

        let bottomVC = fromViewController
        let topVC = viewController

        // make sure the view has a CA layer for smooth animation
        topVC.view.wantsLayer = true

        // set redraw policy
        topVC.view.layerContentsRedrawPolicy = .OnSetNeedsDisplay

        // start out invisible
        topVC.view.alphaValue = 0

        // add view of presented viewcontroller
        bottomVC.view.addSubview(topVC.view)

        // adjust size
        topVC.view.frame = bottomVC.view.frame

        // Do some CoreAnimation stuff to present view
        NSAnimationContext.runAnimationGroup({ (context) -> Void in

            // fade duration
            context.duration = 2
            // animate to alpha 1
            topVC.view.animator().alphaValue = 1

        }, completionHandler: nil)

    }

    func animateDismissalOfViewController(viewController: NSViewController, fromViewController: NSViewController) {

        let bottomVC = fromViewController
        let topVC = viewController

        // make sure the view has a CA layer for smooth animation
        topVC.view.wantsLayer = true

        // set redraw policy
        topVC.view.layerContentsRedrawPolicy = .OnSetNeedsDisplay

        // Do some CoreAnimation stuff to present view
        NSAnimationContext.runAnimationGroup({ (context) -> Void in

            // fade duration
            context.duration = 2
            // animate view to alpha 0
            topVC.view.animator().alphaValue = 0

        }, completionHandler: {

            // remove view
            topVC.view.removeFromSuperview()
        })

    }
}

希望这能让您入门!